The innovation networks of city-regions in Europe: exclusive clubs or inclusive hubs?

Which role do city-regions play in European innovation diffusion? We study the evolution of innovation collaborative networks in European city-regions outlining two opposite models: in the exclusive network model city-regions establish a closed network of innovators among themselves; in the inclusive network models city-regions build a network of innovators which includes the peripheral regions. Employing a Temporal Exponential random graph model on 248 regions in the period 2000-2016, we find that the two models coexist. We conclude that in the EU the city-regions act as both engines of generation and diffusion of innovation